Correlation between U/Th and Pb/Os abundance ratios and its application in nuclear cosmochronology

TL;DR

This paper investigates the strong correlation between U/Th and Pb/Os abundance ratios from the r-process, applying it to estimate stellar ages, which align with the universe's known age, thus aiding nuclear cosmochronology.

Contribution

It establishes a robust correlation between U/Th and Pb/Os ratios and applies it to determine ages of metal-poor stars, enhancing methods in nuclear cosmochronology.

Findings

U/Th and Pb/Os ratios are strongly correlated.

Estimated stellar ages range from 11 to 15 Gyr.

Star ages are consistent with the universe's age of 13.8 Gyr.

Abstract

The abundance ratios of radioactive elements U/Th and stable elements Pb/Os from the $r$-process are found to have a strong correlation. This correlation is quite robust with respect to astrophysical conditions. The U/Th-Pb/Os correlation is then applied to provide customized initial abundance ratios U/Th from the observed abundance ratios Pb/Os for six $r$-process enhanced metal-poor stars respectively. Ages of these six metal-poor stars are predicted by the U/Th chronometer, which are approximately between $11$ and $15$ Gyr. Their ages are compatible with the cosmic age of 13.8 billion years predicted from the cosmic microwave background radiation.